|   | 
Details
   web
Records
Author Baudin, K.; Fusaro, A.; Garnier, J.; Berti, N.; Krupa, K.; Carusotto, I:, Rica, S.; Millot, G.; Picozzi, A.
Title Energy and wave-action flows underlying Rayleigh-Jeans thermalization of optical waves propagating in a multimode fiber((a)) Type
Year 2021 Publication EPL Abbreviated Journal EPL
Volume 134 Issue 1 Pages 14001
Keywords BOSE-EINSTEIN CONDENSATION; TURBULENCE; TEMPERATURE; LIGHT
Abstract The wave turbulence theory predicts that a conservative system of nonlinear waves can exhibit a process of condensation, which originates in the singularity of the Rayleigh-Jeans equilibrium distribution of classical waves. Considering light propagation in a multimode fiber, we show that light condensation is driven by an energy flow toward the higher-order modes, and a bi-directional redistribution of the wave-action (or power) to the fundamental mode and to higher-order modes. The analysis of the near-field intensity distribution provides experimental evidence of this mechanism. The kinetic equation also shows that the wave-action and energy flows can be inverted through a thermalization toward a negative temperature equilibrium state, in which the high-order modes are more populated than low-order modes. In addition, a Bogoliubov stability analysis reveals that the condensate state is stable.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0295-5075 ISBN Medium
Area Expedition Conference
Notes WOS:000731468600008 Approved
Call Number UAI @ alexi.delcanto @ Serial 1510
Permanent link to this record
 

 
Author During, G.; Picozzi, A.; Rica, S.
Title Breakdown of weak-turbulence and nonlinear wave condensation Type
Year 2009 Publication Physica D-Nonlinear Phenomena Abbreviated Journal Physica D
Volume 238 Issue 16 Pages 1524-1549
Keywords Weak-turbulence theory; Nonlinear Schrodinger equation; Wave condensation
Abstract The formation of a large-scale coherent structure (a condensate) as a result of the long time evolution of the initial value problem of a classical partial differential nonlinear wave equation is considered. We consider the nonintegrable and unforced defocusing NonLinear Schrodinger (NLS) equation as a representative model. In spite of the formal reversibility of the NLS equation, the nonlinear wave exhibits an irreversible evolution towards a thermodynamic equilibrium state. The equilibrium state is characterized by a homogeneous solution (condensate), with small-scale fluctuations superposed (uncondensed particles), which store the information necessary for “time reversal”. We analyze the evolution Of the cumulants of the random wave as originally formulated by DJ. Benney and P.G. Saffman [D.J. Bentley, P.G. Saffman, Proc. Roy. Soc. London A 289 (1966) 301] and A.C. Newell [A.C. Newell, Rev. Geophys. 6 (1968) 1]. This allows us to provide a self-consistent weak-turbulence theory of the condensation process, in which the nonequilibrium formation of the condensate is a natural consequence of the spontaneous regeneration of a non-vanishing first-order cumulant in the hierarchy of the cumulants' equations. More precisely, we show that in the presence of a small condensate amplitude, all relevant statistical information is contained in the off-diagonal second order cumulant, as described by the usual weak-turbulence theory. Conversely, in the presence of a high-amplitude condensate, the diagonal second-order cumulants no longer vanish in the long time limit, which signals a breakdown of the weak-turbulence theory. However, we show that all asymptotic closure of the hierarchy of the cumulants' equations is still possible provided one considers the Bogoliubov's basis rather than the standard Fourier's (free particle) basis. The nonequilibrium dynamics turns out to be governed by the Bogoliubov's off-diagonal second order cumulant, while the corresponding diagonal cumulants, as well as the higher order cumulants, are shown to vanish asymptotically. The numerical discretization of the NLS equation implicitly introduces an ultraviolet frequency cut-off. The simulations are in quantitative agreement with the weak turbulence theory without adjustable parameters, despite the fact that the theory is expected to breakdown nearby the transition to condensation. The fraction of condensed particles vs energy is characterized by two distinct regimes: For small energies (H << H-c) the Bogoliubov's regime is established, whereas for H less than or similar to H-c the small-amplitude condensate regime is described by the weak-turbulence theory. In both regimes we derive coupled kinetic equations that describe the coupled evolution of the condensate amplitude and the incoherent field component. The influence of finite size effects and of the dimensionality of the system are also considered. It is shown that, beyond the thermodynamic limit, wave condensation is reestablished in two spatial dimensions, in complete analogy with uniform and ideal 2D Bose gases. (C) 2009 Elsevier B.V. All rights reserved.
Address [Duering, Gustavo; Rica, Sergio] Univ Paris 06, Ecole Normale Super, Phys Stat Lab, F-75005 Paris, France, Email: rica@lps.ens.fr
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0167-2789 ISBN Medium
Area Expedition Conference
Notes WOS:000268621400003 Approved
Call Number UAI @ eduardo.moreno @ Serial 61
Permanent link to this record
 

 
Author Kalyaan, A.; Pinilla, P.; Krijt, S.; Banzatti, A.; Rosotti, G.; Mulders, G.D.; Lambrechts, M.; Long, F.; Herczeg, G.J.
Title The Effect of Dust Evolution and Traps on Inner Disk Water Enrichment Type
Year 2023 Publication Astrophysical Journal Abbreviated Journal Astrophys. J.
Volume 954 Issue 1 Pages 66
Keywords PLANETESIMAL FORMATION; TRANSITION DISKS; ALMA SURVEY; GAP EDGES; PROTOPLANETARY; ICEPLANETS; SUBSTRUCTURES; CONDENSATION; FILTRATION
Abstract Substructures in protoplanetary disks can act as dust traps that shape the radial distribution of pebbles. By blocking the passage of pebbles, the presence of gaps in disks may have a profound effect on pebble delivery into the inner disk, crucial for the formation of inner planets via pebble accretion. This process can also affect the delivery of volatiles (such as H2O) and their abundance within the water snow line region (within a few au). In this study, we aim to understand what effect the presence of gaps in the outer gas disk may have on water vapor enrichment in the inner disk. Building on previous work, we employ a volatile-inclusive disk evolution model that considers an evolving ice-bearing drifting dust population, sensitive to dust traps, which loses its icy content to sublimation upon reaching the snow line. We find that the vapor abundance in the inner disk is strongly affected by the fragmentation velocity (v( f)) and turbulence, which control how intense vapor enrichment from pebble delivery is, if present, and how long it may last. Generally, for disks with low to moderate turbulence (a = 1 x 10(-3)) and a range of v( f), radial locations and gap depths (especially those of the innermost gaps) can significantly alter enrichment. Shallow inner gaps may continuously leak material from beyond it, despite the presence of additional deep outer gaps. We finally find that for realistic v( f) (=10 m s(-1)), the presence of gaps is more important than planetesimal formation beyond the snow line in regulating pebble and volatile delivery into the inner disk.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0004-637X ISBN Medium
Area Expedition Conference
Notes WOS:001053337200001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1870
Permanent link to this record
 

 
Author Picozzi, A.; Rica, S.
Title Condensation of classical optical waves beyond the cubic nonlinear Schrodinger equation Type
Year 2012 Publication Optics Communications Abbreviated Journal Opt. Commun.
Volume 285 Issue 24 Pages 5440-5448
Keywords Nonlinear optics; NLS equation; Optical turbulence; Condensation of optical waves
Abstract A completely classical nonlinear wave is known to exhibit a process of condensation whose thermodynamic properties are analogous to those of the genuine Bose-Einstein condensation. So far this phenomenon of wave condensation has been studied essentially in the framework of the nonlinear Schrodinger (NLS) equation with a pure cubic Kerr nonlinearity. We study wave condensation by considering two representative generalizations of the NLS equation that are relevant to the context of nonlinear optics, the nonlocal nonlinearity and the saturable nonlinearity. For both cases we derive analytical expressions of the condensate fraction in the weakly and the strongly nonlinear regime. The theory is found in quantitative agreement with the numerical simulations of the generalized NLS equations, without adjustable parameters. (C) 2012 Elsevier B.V. All rights reserved.
Address [Picozzi, Antonio] Univ Bourgogne, Lab Interdisciplinaire Camot Bourgogne, CNRS UMR 5027, Dijon, France, Email: antonio.picozzi@u-bourgogne.fr;
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0030-4018 ISBN Medium
Area Expedition Conference
Notes WOS:000311196500124 Approved
Call Number UAI @ eduardo.moreno @ Serial 255
Permanent link to this record